<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>基本选择器</title>
  <style>
    /* 标签选择器*/
    div{
     width: 300px;
    height: 200px;
    border: 1px solid firebrick;
    background-color: yellow
    ;
    }
    /* 类标签 */
    .red{
      color: red;
    }
    #div{
      width: 200px;
      height: 200px;
      background-color: #888;
   
    }
  </style>
</head>
<body>
    <div class="red">div1</div>
    <p class="red" >段落</p>
    <span class=" red">span标签 </span>
    <div id="div">div</div>
</body>
</html>
